1. Field of the Invention
The present invention relates, in general, to an orthodontic bracket base and an orthodontic bracket having the base, and more particularly, to an orthodontic bracket base which has a characteristic of excellent adhesion to a tooth surface and can be easily separated from the tooth surface after orthodontic treatment is finished, and to an orthodontic bracket having the base.
2. Description of the Prior Art
As is generally known in the art, the parts used for correcting an irregularly arranged set of teeth mostly include orthodontic brackets (hereinafter, referred to as “brackets”), each of which is secured to a tooth surface, and an arch wire which connects the brackets to one another so as to apply tension force to thereby correct the irregular set of teeth.
Referring to FIG. 1, a metal bracket is illustrated as one example of a conventional bracket. As can be seen from FIG. 1, the bracket comprises a base 1 which has an adhesion surface 1a to be brought into dose contact with a tooth surface, a slot 2 which is defined on the rear surface of the base 1 to allow a wire (not shown) to be fitted therein, and wings 3 which are arranged on both sides of the slot 2 to allow a securing member for securing the wire, such as an elastic O-ring, a bolt, and so forth, to be mounted thereto.
Basically, the bracket must not be easily separated from the tooth surface while orthodontic treatment is underway (hereinafter, referred to as an “adhesion function”), and must be easily separated from the tooth surface after orthodontic treatment is finished (hereinafter, referred to as a “separation function”).
As a method for improving the adhesive function of the bracket, that is, for allowing the adhesion surface of the base to be adhered to the tooth surface with a sufficient adhesive strength, a first method of improving the functionality of an adhesive, a second method of changing the contour of the adhesion surface such as by forming prominences and depressions or slits or grooves on the adhesion surface of the base, a third method of using mesh prepared by weaving thin wire, etc. are currently known in the art.
For example, in Korean Utility Model Registration No. 20-378093, in order to improve the adhesion strength of a bracket, prominences and depressions are formed on an adhesion surface, and mesh is heat-fused onto the prominences and depressions.
However, in this conventional technique, special emphasis is placed only on improving the adhesive function, and the importance of the separation function is not appropriately considered. Therefore, a problem occurs in that it is difficult to separate the bracket from the tooth surface to the extent that the adhesion strength of the bracket with respect to the tooth surface is improved. Further, serious damage to the tooth surface may occur.
In Japanese Patent Laid-open Publication Gazette 2004-329936, in order to improve the separation function of the bracket, disclosed is a technique of making the adhesive force smaller adjacent to the edges of the adhesion surface of a base compared to other portions.
Nevertheless, in this conventional technique, special emphasis is placed only on the improvement of the separability of the bracket, and measures for solving the problem caused by the degradation of the adhesive function which results from the improvement of the separation function are not provided.
Meanwhile, FIG. 2 illustrates another example of the conventional bracket, which is a metal-reinforced ceramic bracket. Since the ceramic bracket is transparent and has an aesthetically appealing outer appearance, it is preferable to a metal bracket.
Referring to FIG. 2, the bracket comprises a base 1, a slot 2 and wings 3. The base 1 and the wings 3 are mainly made of ceramic. A metal insert 4 for reinforcing the strength of the bracket is installed in the slot 2. The insert 4 also has a slot 2a which corresponds to the slot 2. The unexplained reference numeral 5 designates a dimple portion on which a bracket identification marking is provided.
Even in the type of bracket shown in FIG. 2, a drawback exists in that the insert 4 is likely to be released from its normal installation position due to the movement of a wire fitted into the slot 2a of the insert 4 in the course of performing ligation.